Relationship Between RR Intervals and Early Diastolic Mitral Annulus Velocities in Atrial Fibrillation Patients Who do not Have Significant Valvular Diseases

BACKGROUND AND OBJECTIVES: Irregular RR intervals in atrial fibrillation (AF) results in beat to beat changes in hemodynamical parameters. Early diastolic mitral annulus velocity (E') is one of the parameters that represent diastolic function of the left ventricle (LV). In this study, we have investigated the effects of continuous changes of systolic functions in AF on the diastolic functions of the LV. SUBJECTS AND METHODS: E' (35-40 beats) was recorded in 31 AF patients that did not have significant valvular heart diseases. The relationships between preceding RR intervals (RR-1) or pre-preceding RR intervals (RR-2) and E's were obtained using a logarithmic function. RESULTS: Slopes between RR-1 and E' varied from -1.62 to 1.04 in total coordinates. In the logistic regression analysis patients with negative slopes were found to have a larger left atrial size than patients with positive slopes (5.5+/-0.67 cm vs. 4.9+/-0.56 cm, p=0.02). Slopes were negatively related with mean RR intervals in the Pearson correlation analysis (r=-0.40, p=0.028). Slopes between RR-2 and E' were also variable and were not associated with other parameters. CONCLUSION: Beat to beat changes in systolic functions derived from irregular RR intervals in AF had variable effects on diastolic functions among patients. The relationship between RR-1 and E' was associated with LA sizes and mean RR intervals.

The correlation between midwall function and carotid intima-media thickness in hypertensive patients / 대한내과학회지

BACKGROUND/AIMS: In hypertensive patients, LV ejection fraction may be normal or high, thus limiting assessment of prognosis. This has led to a growing body of research using LV midwall fractional shortening (MWS) instead. The current study aims to assess LV midwall function in hypertension patients and to study its correlation with the intima-media thickness (IMT) of the carotid artery. METHODS: Echocardiography and ultrasonography of the carotid artery were conducted to establish a group of hypertension patients without major complications (n=136) and a control group (n=48). LV MWS was determined using two cylindrical models, and the IMT was measured. RESULTS: Compared with normotensive subjects, hypertensive adults exhibited higher LV mass index and lower LV MWS. A statistically significant correlation was found between the LV MWS and the average IMT in hypertension patients (r=-0.41). There was also a significant negative correlation among the maximum IMT (r=-0.40), LV mass index (r=-0.32), age (r=-0.31), and systolic blood pressure (r=-0.22). Regarding the prevalence of plaque in the carotid artery, the stage 1 hypertension group exhibited 16.7% prevalence, and the stage 2 hypertension group 32.9% prevalence, thereby showing far higher figures than the control group's 4.2%. CONCLUSIONS: The LV MWS in hypertension patients underwent a statistically significant decrease, and the correlation between LV MWS and the IMT of the carotid artery was found to be high compared with the general blood pressure index. LV MWS can be used as an indicator to assess the prognosis of hypertension patients.

Association of New Parameters Derived from Relation between RR intervals and Left Ventricular Performances with Heart Failure in Patients with Atrial Fibrillation and Normal Systolic Function

BACKGROUND AND OBJECTIVES: Heart failure (HF) may occur in atrial fibrillation (AF) patients with a normal left ventricular (LV) systolic function if the diastolic function is impaired. The association of new parameters from the relationship between the preceding RR interval (RR-1) and LV outflow peak ejection velocity (Vpe) with systolic function has been reported. The aim of this study was to observe whether these parameters were associated with HF in AF patients with a normal systolic function. SUBJECTS AND METHODS: AF patients with a normal systolic function were divided into two groups according to the presence (n=16) or absence (n=30) of a history of HF. From the logarithmic equation between RR-1 and Vpe, the slope, Vpe at RR-1 second (Vpe-1), and Slope/Vpe-1 were calculated. RESULTS: Patients with a history of HF were older (p=0.037) and tended to more frequently have hypertension (p=0.063) than those with no history of HF. The ejection fractions were similar between the two groups. In the coordinates with RR-1 from 0.6 to 1 second, the slope tended to be steeper (p=0.074) and slope/Vpe-1 was higher in patients with a history of HF (p=0.011). The Vpe-1 was similar between the two groups (p=0.66). A multiple forward logistic regression analysis showed that slope/Vpe-1 was the only independent variable associated with the occurrence of HF. Slope/Vpe-1 was related with aortic regurgitation, HF history, and the interventricular septal thickness in a multiple stepwise regression analysis. CONCLUSION: New parameters from the relationship between the RR intervals and LV performances were associated with the occurrence of HF in AF patients with a normal systolic function. This finding suggests that these parameters may be related with the LV diastolic function.

The Value of the First Two Minutes of Heart Rate Recovery after Exercise Treadmill Test in Predicting the Presence and Severity of Coronary Artery Disease

BACKGROUND AND OBJECTIVES: The recent data has revealed that the first 1 minute and 2 minutes of heart rate recovery of patients who are being evaluated for chest pain and asymptomatic adults are associated with the overall mortality. However, the clinical significance of the heart rate recovery after exercise testing during the first 2 minutes for predicting the presence or severity of coronary artery disease and the correlation with the Duke treadmill score (DTS) have not been fully evaluated. SUBJECTS AND METHODS: The study population included 39 patients with significant coronary artery stenosis and 39 subjects with normal coronary arteries. All of them underwent a tread-mill exercise testing prior to coronary angiography. The differences in the heart rate recovery and the DTS between the two groups were investigated. The heart rate recovery and DTS between the multivessel disease group and single vessel disease group were also investigated. RESULTS: The heart rate recovery during the second minute (calculated by the heart rate at 1 minute-the heart rate at 2 minute) after exercise and the DTS were significantly lower in the coronary artery disease group. These parameters were also significantly lower in the multivessel disease group than those in the single vessel disease group. The heart rate recovery during the second minute and the DTS had positive linear correlation (R=0.281, p<0.05). CONCLUSION: In this study, the heart rate recovery during the second minute was considered to be an additional important variable to predict the presence and severity of coronary artery disease.